Field of the Invention
The present invention relates to an image pickup apparatus capable of obtaining an all-in-focus image by focus bracketing.
Description of the Related Art
Previously, an image pickup apparatus which performs an all-in-focus image shooting has been known. The all-in-focus image shooting is a shooting, by the image pickup apparatus, in which a plurality of images that have different in-focus positions over an entire region of a focusable object distance and only a focused region is extracted from each image to synthesize an image to obtain the image focused on an entire shooting region. In the all-in-focus image shooting, it is necessary to shoot a plurality of images by one shooting operation, and therefore it may take a long time to perform the all-in-focus image shooting.
Japanese Patent Laid-open No. 2008-271240 discloses a configuration in which a predetermined bracketing width (moving amount of a focus lens) is set to be decreased when a depth of field in the image shooting is shallow, and is to be increased when the depth of field is deep. According to the configuration disclosed in Japanese Patent Laid-open No. 2008-271240, changing the bracketing width depending on the depth of field in the image shooting, the number of shootings can be reduced when the depth of field is deep.
However, in the configuration disclosed in Japanese Patent Laid-open No. 2008-271240, for example when the shutter speed is slow, a shooting time per one image increases and thus the time required for one all-in-focus image shooting cannot be reduced in some cases.